1. Field of the Invention
The present invention relates to an audio output circuit in an electronic apparatus equipped with a composite display function. And more particularly, it relates to a novel audio output circuit so contrived that, when audio signals are outputted in an electronic apparatus having a composite display function, any audio signal relative to a desired one of pictures displayed on screen regions can be selectively heard through a speaker, or a plurality of audio signals relative to individual pictures can be heard simultaneously through individual speakers.
2. Description of the Prior Art
In digital television receivers and so forth, there is known a type having a picture-in-picture function with a parent screen region and a child screen region provided on a single monitor display screen, wherein different pictures can be displayed individually on such separate screen regions.
In a television receiver a shown in FIG. 8, for example, its entire display screen b is divided into a parent screen b.sub.p of a major area and a child screen b.sub.c of a minor area defined at the lower left corner, and a picture of another broadcast program or the like different from a picture of the program on the parent screen b.sub.p can be displayed on the child screen b.sub.c so that both pictures are watchable simultaneously.
In the conventional television receiver known heretofore, there exists a problem that an audio signal relative to the picture on the child screen can be heard only through an earphone (or headphones).
In this example, the output from the speaker c in the television receiver a is only the sound relative to the picture on the parent screen b.sub.p, so that when it is desired to hear the sound relative to the picture on the child screen b.sub.c, a plug of an earphone d needs to be connected each time to an earphone jack in the television receiver to consequently require an additional effort on the part of the user.
Meanwhile, for hearing the sound relative to the picture on the child screen b.sub.c through the speaker c without using any earphone or the like, it is necessary to display the relevant picture on the parent screen b.sub.p to eventually necessitate swapping of the pictures between the parent screen b.sub.p and the child screen b.sub.c, hence lowering the degree of freedom in selection of the video signal and the audio signal.